Field of the Invention
The present invention relates to a canister storing fuel evaporation gas which is generated when an engine stops and a filter mounted in the canister, and more particularly, to an insert type filter for a canister which is replaceably installed into the canister of the vehicle and is mounted in a form inserted into the canister and a canister having the filter.
Description of Related Art
Fuel evaporation gas is generated from a fuel tank, and the like in a state in which an engine of a vehicle stops. When the fuel evaporation gas is emitted into the atmosphere, air pollution occurs. Therefore, the fuel evaporation gas is stored in a canister which is installed in the vehicle and then is supplied to the engine at the time of an operation of the engine so as to be combusted.
FIG. 1 illustrates a layout of a system for treating fuel evaporation gas of a vehicle in which a gasoline engine is equipped. The fuel evaporation gas generated from a fuel tank 4 is collected in a canister 100 and a purge control solenoid valve (PCSV) 5 which is operated by an electronic control unit (ECU) 8 is opened at the time of a purge of the engine 1. When the PCSV 5 is opened, air introduced from the outside through a vent line 6 by a negative pressure in an intake pipe 2 is supplied to a canister 100 to supply the fuel evaporation gas collected in the canister 100 to the intake pipe 2 and combust the collected fuel evaporation gas in the engine 1. Non-explained reference number 3 is a throttle valve which controls an amount of air introduced into the engine 1 and non-explained reference numeral 7 is an air filter which filters foreign materials included in the air introduced from the outside.
Meanwhile, FIG. 2 illustrates a structure of the canister 100. The canister 100 includes: a case 101 configured to have a barrier rib 102 formed therein; active carbon 103 configured to be filled in the case 101; an air inlet 104 configured to be connected to a vent line 6; a gas inlet 105 configured to be introduced with the fuel evaporation gas from the fuel tank 4; a gas outlet 106 configured to emit the fuel evaporation gas collected in the canister to the intake pipe 2; an upper filter 108 configured to be installed at the air inlet 104, the gas inlet 105, and the gas outlet 106; and a lower filter 109 configured to be elastically supported under the case 101 to prevent the active carbon 103 from flowing.
In accordance with the related art, the upper filter 108 is fused to the inside of the case 101 with an ultrasonic wave and therefore the upper filter may not be replaced later. For example, when the upper filter 108 at the air inlet 104 side is deposited with foreign materials, dust, and the like and thus the air inlet 104 stops, only the upper filter 108 may not be replaced and therefore the overall canister 100 cannot but be replaced.
When the PCSV 5 is opened and purged in a state in which the air inlet 104 side stops by foreign materials, and the like, the negative pressure in the intake pipe 2 is delivered to the fuel tank and thus the pressure in the fuel tank 4 is lower than an atmospheric pressure, such that the fuel tank 4 may be damaged.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.